Firefighters were called to a large vegetation blaze at a Christchurch forest park on Thursday night.

Fire and Emergency NZ received multiple calls around 8.30pm about a fire on the perimeter of Waitākiri/Bottle Lake Forest Park.

Three fire engines, two water tankers and a rural pump were sent to the scene, with the first arriving appliance describing the blaze as the size of a bus.

It said the fire may have started on the beach.

The blaze was not close to any structures.

In August, Civil Defence and FENZ warned Christchurch City Council that Bottle Lake Forest Park could be problematic in a fire.

FENZ Canterbury district commander Dave Stackhouse said at the time people may have trouble escaping the park during a fire.

"We have an evacuation plan for [Bottle Lake] as well, but of course, with heavy fire loading driven by the wind conditions we see in Canterbury, [fire] just rips in pretty quick in there and it is hard to for us to contain that, because the amount of heat it generates is unstoppable, until we can get it controlled and pinched down," he said.

-With RNZ